The whole area is a rectangle one. In order to get the area of a rectangle, the formula is length multiplied by the width. The length of the area is 7.5 meters and the width is 5.3 meters. Covering the whole area with foam needs 39.75 square meters of it.
I hope this helps you
x.3x+x.(-1)+5.3x+5.(-1)-(x^2-2.4.x+16)
3x^2-x+15x-5-x^2+8x-16
2x^2+22x-21
The answer is 9
both 81 and 63 are dividable by 9, and nothing higher